1. International Atomic Energy Agency, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115, Vienna (1996).
2. European Commission, Practical Use of the Concepts of Clearance and Exemption-Part II Application of the Concepts of Exemption and Clearance to Natural Radiation Sources, Radiation Protection 122, Luxemburg (2001).
3. International Atomic Energy Agency, Application of the Concepts of Exclusion, Exemption and Clearance, RS-G-1.7, Vienna (2004).
4. International Atomic Energy Agency, Derivation of Activity Concentration Values for Exclusion, Exemption and Clearance, SR-44, Vienna (2005).
5. United Nations Scientific Committee on the Effects of Atomic Radiation, Sources and Effects of Ionizing Radiation, UNSCEAR 2000 Report Vol. I (2000).